Nanotubes and the process for their production is known according to the current state-of-the-art. The nanotubes are needle-shaped tubes with a length of 1,000 xc3x85, for example, and a diameter of a few 100 xc3x85. Nanotubes are separated or separable and do not all point in one specific direction. Known are also sclerogenous structures, which are created by a network of tubes. The tubes of such a sponge-like structure have an inside diameter that is growth-limited to be not larger than 80 xc3x85.
The currently known nanotubes and also the above-mentioned sclerogenous structures consist mainly of carbon and are produced by arcing. Reference is made to this in JP-A-071 65 406, JP-A-071 97 325 and in scientific discussions published in NATURE, volume 358, pages 220 through 222 and volume 363, pages 603 through 605. Known are also nanotubes made of gold or titanium oxide, as it can be seen in a publication of Langmuir, volume 12, number 6, 1996, pages 1411 through 1413.
Single nanotubes may be used, for example, to catch individual molecules. Nanotubes may be handled individually or they may be pasted on for microscopic examinations. However, carbon nanotubes have specifically the disadvantage that they are unstable relative to oxidizing effects.
The innovative nanotubes are characterized in that they are made of a transition metallic oxide. Such nanotubes may also be produced to be separable, whereby they are essentially not aligned in a three-dimensional manner. They are considerably more oxidation stable than carbon nanotubes and have additional advantageous characteristics and applications, which cannot be found in carbon nanotubes. In particular, the innovative nanotubes have distinct redox activities, which offer a number of novel uses and applications. It has been shown that nanotubes made of mixed-valence vanadium oxide are especially advantageous. They are especially oxidation stable and may be produced in form of a solution.
Innovative nanotubes and specifically nanotubes made from mixed-valence vanadium oxide are well suited as active agents for catalytic reactions. Special advantageous applications are the ones for the process of redox reaction in batteries as storage electrodes or in high capacity capacitors. Additonal advantageous uses of the innovative nanotubes may be seen in the process for exchange reactions of the tube content, which may include molecules, metallic clusters, metalloid clusters or polymers, and specifically so-called molecular wires. The nanotubes act in a size-selective manner so that proteins of a certain size may be placed into the tubes.
The invention, according to the minor claims, relates also to an advantageous process for the production and preferred use of nanotubes.